Congratulations!! Will keep our fingers crossed that this is the "one"!!

I would think that since the baby will be a part of Spanky's life that you should certainly socialize the two of them. I would be very, very careful until the baby is older & "sturdier" to trust the larger dog too much. You can never tell how they really feel and will react to new arrivals. When we brought Toto home [at about that size] we were just soooo protective of her and we just "toughtened" up and disregarded everyone that thought we were silly! We still do!
We found that using an X-pen on a heavy duty shower curtain worked best for us. It gives you the freedom to configure it the way that works best for you and the baby and also gives you enough room to place all the comfort things that will make your baby happy! We kept, and still do, plenty of little blankets handy. If they happen to soil one you can just toss it in the laundry and you have plenty to use. We still don't worry too much about Toto having a sweater/coat on when we are outside because she always wants to be snuggled up in a warm fleece blankie and in our arms or on our lap. If she will be walking, of course, we make sure she is "suited up"!
I know you are excited as we are excited for you. You know us .... we want updates, pics, etc.!